Means and method for bending pipe



Sept. 16, 1930. HARVEY 1,775,762

MEANS AND METHOD FOR BENDING PIPE Filed Feb. 25, 1926 2 Sheets-Sheet lINVENTOR W'- a; B

ATTORNEYS Sept. 16, 1930. H. E. HARVEY MEANS AND METHOD FOR BENDING PIPEFiled Feb. 25, 1926 2 Sheets-Shut 2 I I I l l l l I I I I I I I IINVENTO r/hfi A ORNEYS Fig-4 Patented Sept. 16, 1930 UNITED STATESPATENT OFFICE HARRY E. HARVEY, 0F CLEVELAND, OHIO, ASSIGNOR, BY MESNEASSIGNMENTS, TO STEEL AND TUBES, INCL, OF CLEVELAND, OHIO, A CORPORATIONOF OHIO MEANS AND METHOD FOR BENDING PIPE Application filed February 25,1926.

This invention relates to apparatus for bending pipes and the like. Itmore particularly relates to apparatus for forming the pipe or the likeinto a predetermined curve. I i

An object of the invention is to provide a method and apparatus forbending pipe which will prevent the pipe from flattening or bucklingwhen the bend is made.

Other objects and advantages will hereinafter appear.

This application is a continuation of my copending application, SerialNo. 729,077, filed July 30,1924, as to all matter common to bothapplications.

The invention, as well as its objects and advantages, will be betterunderstood from the description of one practical embodiment thereofwhich is shown by way of illustration in the accompanying drawings, inwhich-'- Fig. 1 is a side elevation of a machine provided with bendingdies which constitute one embodiment of my invention;

Fig. 2 is a'plan view on a larger scale of a part of the machineshown inFig. 1 with the dies separated;

Fig. 3 is a view similar to Fig. 2 but on a still larger scale andshowing the dies in a partly closed position; and

Fig. t is a cross section on line H of Fig. 3. a

The apparatus shown is designed to form a pipe into a compound or ogeecurve and consists of suitable'dies and a machine for operating them.

The drawings represent the bending dies 1 and 2 as applied to abulldozer machine. The machine comprises a bed 3 carrying a stationaryabutment 4 and a horizontally reciprocating crosshead 5 which is drivenfrom an external source of power through reduction gearing 6, cranks 7and rods 8.

Die 1 is illustrated as being'held stationary by being fastened to theabutment while die 2 is attached to the crosshead and reciprocatedthereby along the top of thebed, to and from the stationary die. As thedies shown are intended to form a compound bend in the pipe, the bendingfaces are in Serial No. 90,457.

the form of an ogee curve, the convex portion 9 of the stationary diebeing opposite and complementary to the concave portion 10 of themovable die, and the concave portion 11 of the stationary die beingopposite and complementary to the convex portion 12 of the movable die.The faces are provided with semicircular grooves l and 2* for thereception of the pipe.

A plunger 13 is provided-in concave portion 10 of the movable die and isurged outward by spring 14, normally extending as far as the depth ofthe concavity of the die. The concave portion of the stationary die isprovided with a similar plunger 15 urged outward by spring 16. Thesprings are stiff enough to bend the sections of the pipe contacted bythe plungers, so that the plungers touch the die faces" opposite beforethe springs yield. Consequently, the plungers give theportions of thepipe which they contact its complete bend before any other portions arebent, and thereafter clamp these portions tightly against the dies,holding them thus throughout the remainder of the bending operation.

As the dies are moved together, the unclamped portions of the pipenearest the plungers are first bent about the convex portions of thedies, and as the dies ap roach each other increments successively recding from said plungers are bent until the dies touch when the entirebend has been formed.

It will also be seen that as the dies are moved together, after theplungers have gripped the pipe, thedistance between the grippedportionsis increased, maintaining the intermediate portion under tension whilethe bend is made, there being a localized stretching of the pipe duringthe bending operation as well as a slight longitudinal sliding of thepipe past theplungers. This tension probabl helps in preventing the pipefrom buckling but the bending of relatively short portions at any onetimeand the supporting of those already bent are probably mainlresponsible for preventing deformation.

The die may be formed in any suitable or convenient manner. As shown inFigs. 3

'die. A bar 30 is provided with screws for adjusting the tension ofsprings 14 and 16.

Of course, for making longer or sharper bends, the dies may be providedwith groups of a plurality of plungers arranged so that the certainplungers of each group engage the pipe first and adjacent plungers aresuccessively brought into engagement. Many other modifications andvariations will readily become apparent to those skilled in this art andI, therefore, do not limit myself to the precise embodiment shown butclaim as my invention all embodiments coming within the scope of theappended claims. Other methods of actuating the plunger besides springsmay be used Without departing from the spirit of this invention. Forinstance air or other fluid pressure could be employed.

I claim:

1. A pipe bender comprising two relative ly movable, complementary dieseach provided with a concave portion, said dies being provided in theiradjacent faces with grooves for receiving the pipe to be bent and springpressed plungers extensible from the concave "faces of each die.

2. A pipe bender comprising two relatively movable, complementarydieswith undulant pipe engaging surfaces, and spring pressed plungersextending from the trough of each undulation of each die.

3. A pipe bender comprising two relatively movable, complementary dieswith undulant pipe engaging surfaces, and spring pressed plungersextending from the trough of each undulation of each die, said plungersnormally extending into alignment with the tcirests of the undulationsof their respective 4. A pipe bender comprising a bed, an abutmentcarried thereby, a crosshead reciprocating on the bed, two complementarydies,

one secured to the abutment and the other to the crosshead, each diehaving a sinusoidal working face, the concave portions of the faceshaving extensible, spring pressed sections. 5. A pipe bender havinsinusoidal fixed and mova le dies between which pipe is bent, and meansextending from each die to resiliently engage the pipe and hold itagainst the convex portions of the opposite die during bending.

6. A pipe bender having complementary 8. The method of bending pipewhich comprises tightly gripping and slightly bending the empty pipe ata plurality of spaced points simultaneously, then maintaining the grip,and simultaneously bending the pipe intermediate and outside saidpoints.

9. The method of bending pipe which comprises clamping the pipe inrecesses of relatively movable dies at spaced points and then moving thedies longitudinally together to bend the pipe between said points intoconformity with the configuration of the die recesses.

10. The method of bending pipe which consists of successively andcompletely bending increments thereof from the crests to the nodes ofthe finished bends.

11. The method of bending pipe which consists of gripping and bendingthe pipe for short distances at spaced points and then relatively movingthe gripping means in paths substantially transverse to the pipe thusbending the pipe intermediate said points while maintaining it undertension.

12. The method of bending pi e which consists of bending short lengths othe pipe completely and thereafter bending the pipe between said shortlengths.

13. The method of bending pipe which comprises gripping the pipe bymovable protruding die portions against rigid opposing die faces, andthen moving the dies together to bend the pipe between the die faces.

In'testimony whereof I hereunto afiix my signature this 11th day ofFebruar 1926.

HARRY E. HA VEY.

complementary

